CODEWITHSUNDEEP
javaspringtransactionsconcurrencysynchronization
Altug
Altug

Reputation: 1743

Spring @Transactional concurrency


class MyService {



public void a() {
     synchronized(somekey) {
        b(); 
     }
  }



@Transactional(propagation = Propagation.REQUIRES_NEW)
  public void b() {
    ...do DB works...
  }
}

My aim is

    1 - get the key
    2 - start transaction
    3 - commit transaction
    4 - release the key

When i call a() method from outside, transaction doesn't work.

Any suggestions ?

Thanks.

Upvotes: 2

Views: 3081

Answers (5)

Jaydeep Patel
Jaydeep Patel

Reputation: 2423

Method call to b() is internal call not on transactional proxy as said by Henning.

Whole thing is explained in this blog post.

Upvotes: 0

Henning
Henning

Reputation: 16341

Unless you're using code weaving, this can't work.

The default way Spring handles transactions is through AOP proxies. The call to a transactional method goes like this:

 caller --> ProxyClass.a() --> YourClass.a()

If you call another method on the same object, you're not going through the proxy, so there is no transactional behaviour.

 caller --> ProxyClass.a() --> YourClass.a() --> YourClass.b()

If you don't want to use AspectJ, you can get the proxy object using AopContext.currentProxy().

Upvotes: 5

vrm
vrm

Reputation: 1422

If you want to call b() inside of a(), and you want to make b() transactional, you have to put it into separate class.

Upvotes: 0

jvdneste
jvdneste

Reputation: 1677

Not 100% sure. I think all @Transactional calls must be done on the same thread that a transaction started on. I know for certain that @Transactional doesn't work across threads. (I guess by design)

Upvotes: 1

duffymo
duffymo

Reputation: 308998

I'm curious as to the nature of the key. Why is the service generating it? Wouldn't an alternative design put that in the database?

It's hard to tell exactly what's wrong without an error message.

Upvotes: 0

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